1. Technical Field
The invention relates to a virtual image display device that provides, to an observer, an image formed by an image element and the like, in a state of being mounted on the observer.
2. Related Art
As an virtual image display device or a head mounted type display device such as a head-mounted display to be mounted on the head of an observer, for example, as described in JP-A-8-327940, a closed type with a wide visual field that achieves a thin optical system with a wide angle of view by providing a partial optical folding portion utilizing a half mirror has been known. Note that, the head-mounted display is also described as an HMD in the following.
However, in the HMD, when reduction in size or thickness of a device is attempted while a thin optical system with a wide angle of view is achieved, a burden on the optical system increases. That is, a curved surface shape or a refractive index of a lens configuring the optical system is preferably set to easily obtain power.